Improved Active Tagging Non-Destructive Evaluation Techniques for Full- Scale Structural Composite Elements

摘要

An on-site particle tagging non-destructive evaluation (NDE) technique has been developed for health monitoring of a full-scale structural element of glass-fiber reinforced plastics (GFRP) composites in which conventional NDE approaches are not very effective. Unlike conventional passive tagging NDE inspection, the technique uses an electromagnet exciter to interrogate tagged composites. A laser Doppler vibrometer is used for high- speed and non-contact surface vibration detection. An accept-reject criteria based on the signature pattern difference of a healthy and a damaged structure is then applied to extract an index of the health of the structural elements. The experimental results of the active particle tagging inspection shows a variation in the dynamic response of the specimens when defects and/or damage are presents. The variation could be used to diagnose and to monitor the integrity of materials.